Radio communication means between elevator cage and motor control



Aug. 31, 1965 P. A. CUMMINS 3,203,506

RADIO COMMUNICATION MEANS BETWEEN ELEVATOR CAGE AND MOTOR CONTROL Flled Aug. 15, 1962 2 Sheets-Sheet 1 gwqggL 8\ .15 TRANSMITTER "QMOTOR CONTROL I GRECEIVER [Mv/EUToR PETE R ANTHw/V Y COMM/N5 Aug. 31, 1965 P. A. CUMMINS 3,203,505

RADIO COMMUNICATION MEANS BETWEEN ELEVATOR CAGE AND MOTOR CONTROL Filed Aug. 15, 1962 2 Sheets-Sheet 2 7 -41 ge r u rggaL 8\ STRANSMITTER w E x WQMOTOR CONTROL 1 6 RECEIVER PETER Awmwv com/v1 lA/S United States Patent 3,203,506 RADIO COMMUNICATION MEANS BETWEEN ELEVATOR CAGE .A'ND MOTOR CONTROL Peter Anthony Cummins, Aldershot, England, assignor of a joint interest to A.C.E. Machinery Limited, London, England, a British company Filed Aug. '15, 1962, Ser. No. 217,167 Claims priority, application Great Britain, Aug. 16, 1961, 29,5-51/61 1 Claim. (Cl. 187-29) This invention relates to an improved means for communicating between relatively fixed and movable members and in particular to a control system for lifts and other installations where a travelling member is con strained to move over a predetermined path.

An object of the invention is to provide improved means for transmitting the control signals from the cage or travelling member of a lift, hoist or elevator to the stationary control panel associated with the hoisting mechanism. These signals are normally transmitted over an electric cable, one end of which is attached to the cage or travelling member and the other end to the tower, shaft or other structure in which the cage travels.

The invention provides for this purpose an electronic signalling system which requires no metallic connection between the cage and the tower or shaft other than that provided by the hoisting cables and guide rails, thus eliminating the need for the electric cable before mentioned.

Two embodiments of the invention as applied to a lift will now be described with reference to the accompanying drawings wherein FIGS. 1 and 2 show diagrammatically the two respective embodiments.

Referring to FIG. 1 there is attached to one of the inner faces of the shaft or tower 1 and insulated electrically from it, a continuous metallic conductor 2 in the form of a channel or other convenient section to provide rigidity, and running the whole length of the tower. The side of the cage 3 has attached to it and also insulated electrically therefrom a similar metallic conductor 4 of a length approximately equal to the height of the cage. These conductors are positioned so that they are adjacent and separated by a small gap which, however, need not remain precisely constant as the cage travels up and down the shaft.

The metallic strip 4 attached to the cage is connected to the output of a transmitter 5 incorporating an electronic oscillator operating at a relatively low radio frequency. The strip 2 associated with the tower or shaft is connected to the input terminal of a receiver 6 tuned to the same frequency. By virtue of the electrical capacitance existing between the two conductors 2 and 4 a circuit is completed which enables signals to be transmitted without metallic contact taking place. The return circuit is completed through the metal structure of the tower or shaft 1, the hoisting cables 7 and the guide rails (not shown) for the cage 3.

By means of a control unit in the form of a switch 8 (or a push-button set) the radio frequency signal or carrier, is modulated with a number of audio frequencies each of which is associated with a particular control function. Electronic filters in the receiver 6 separate these audio frequency signals and cause them to operate relays in a motor control box 9 which in turn operate the main power contactors for the lift motor.

In order to provide the necessary safety interlock, the electrical supply to the transmitter 8 is preferably taken via the gate lock switch on the cage. The supply itself is most conveniently drawn from a battery although a self contained generator might be employed instead.

The only difference between the embodiment just described and that shown in FIG. 2 concerns the means for making a capacitive coupling between the cage and tower. In the second embodiment, a length of steel wire rope 10 covered with an insulating material such as nylon is tensioned between the top and bottom of the lift shaft 1 and is connected to the receiver 6. The transmitter 5 is connected to a metal tube 11 mounted on but insulated from the cage 3. The insulated wire 10 passes through this tube and thus provides the capacitive coupling between the cage and tower.

In carrying out the invention in its broadest aspect, it is to be understood that any method of modulation of the carrier may be used which is capable of' giving multiple channel control.

In carrying out the invention as applied to a lift, it is further to be understood that an additional safety interlock may be obtained by having a relay operated by the carrier itself so that any failure in the electronic system will result in the cutting off of the main power supply.

I claim:

In a lift comprising a tower, a cage adapted to be moved up and down said tower by a motor, motor control means, communication means comprising an electrical conductor tube on said cage extending in the direction of movement of said cage, an electrically insulated conductor passing through said tube and running the length of said lift tower to provide a capacitive coupling between said tube and conductor, a radio frequency transmitter on the cage connected to said tube and a receiver operatively connected to said conductor and said motor control means, a switch assembly for the transmitter mounted on said cage for modulating the transmitter output to produce control signals conveyed by said coupling to the receiver where they are utilized to control said lift motor control means.

References Cited by the Examiner UNITED STATES PATENTS 2,319,627 5/43 Perlman 179-107 2,505, 144 4/50 Rutherford 179-82 FOREIGN PATENTS 1,042,660 11/5 8 Germany.

811,471 4/ 59 Great Britain.

ORIS L. RADER, Primary Examiner.

WALTER L. LYNDE, Examiner. 

